The Discovery Channel has mounted its most ambitious project to date: “Planet Earth,” an 11-episode nature series filmed in HD and featuring never-before-seen animal behaviors and startling views of locations captured on camera for the first time. The project incorporates over 200 locations and 70 camera operators. In the premiere episode, “Pole to Pole,” we watch the sun rise around the world. From African herds migrating hundreds of miles in search of water to desperate animal hunts, the episode examines how the seasons produce the greatest spectacles on Earth. Narrated by Sigourney Weaver.

PLANET EARTH

Sunday, 8 p.m., Discovery

DRAMA

Hospital horror show

Mariel Hemingway does a guest spot on “Law & Order” as a distraught mother who finds her teenage son dead in her hospital room. Cause of death? A brain tumor developed by ovarian cancer present in a bone replacement for his legs. The donor of the bone who carried the cancer died in a car crash. While the dead donor’s remains were to go to a funeral home for cremation, her body parts instead were sold to a clinic for money. A.D.A.’s Jack McCoy (Sam Waterson) and Connie Rubirosa (Alana De La Garza) want to prosecute the doctor who harvested the bad tissue. Yet, his defense of being a public servant to those who could not afford operations proves hard to refute. Jesse L. Martin, Milena Govich, S. Epatha Merkerson and Fred Dalton Thompson also star.

LAW & ORDER

Friday, 9 p.m., NBC

DRAMA

Up on the roof

Lilly (Kathryn Morris) and the other Cold Case detectives get a whopper of an assignment this week. Twenty years after the murder of his son, the father of the boy goes berserk and pushes a sex offender off a building. Then, he claims responsibility for the killing and vows to kill another person every day until the team can solve his child’s murder. Co-starring Danny Pino.

COLD CASE

Sunday, 9 p.m., CBS

COMEDY

A Night at ‘The Office’

Just in case you hadn’t noticed, NBC really likes “The Office.” The network is now repackaging episodes with scenes that wound up on the cutting-room floor and calling them “newpeats.” And now there’s an “Office marathon” which really isn’t a marathon at all, as the string of episodes airing Thursday night is broken by a new broadcast of “Andy Barker, P.I.” at 9:30 p.m. The “marathon” is hosted by Paul Lieberstein, a writer and co-executive producer on the show who also plays Toby Flenderson, the Director of Human Resources at Dunder Mifflin. He’s a good choice as the “Office’ extravaganza centers on personnel nightmares. The encore presentations include “Diversity Day” at 8 p.m., “Healthcare” at 8:30 p.m., “Sexual Harassment” at 9 p.m., “The Injury” at 10 p.m. and “Gay Witch Hunt” at 10:30 p.m.

THE OFFICE MARATHON

Thursday, 8-9:30 p.m. and 10-11 p.m., NBC

5. CATEGORY: REALITY

Beachfront property

This week “Top Design” leaves the Pacific Design Center so the remaining contestants can design a high-end modern hotel room at the upscale Viceroy, way out on the beach in Santa Monica. With its ocean views and minimalist décor, the Viceroy should at least prove a pleasant respite from the narcissistic agonies of West Hollywood. The special guest judge this week is Linda O’Keeffe, Director of Design & Architecture at Metropolitan Home Magazine. She will be joining forces with the already hard-to-please interior designer Jonathan Adler, Elle magazine editor-in-chief Margaret Russell and interior designer Kelly Wearster. Your host is Todd Oldham.

TOP DESIGN

Wednesday, 10 p.m., Bravo

DRAMA

Signing off

In the season finale episode of “What About Brian,” Dave and Deena’s plans for a secret getaway to renew their wedding vows turns chaotic. Meanwhile, Brian and Adam’s babysitting duties for Dave and Deena’s daughters are interrupted when Natasha shows up with a work emergency. Brian (Barry Watson) calls on Stephanie to look after the girls, but when a crisis occurs, he realizes that Laura is the one he should have asked to help. And after Nicole and Deena’s Icing on the Cupcake store starts getting great press, an overwhelmed Nicole finds herself alone and without any help to tend to the many new customers.